chore: catch2-3.4.0

Upgrade to pick up https://github.com/catchorg/Catch2/commit/dc001fa935d71b4b77f263fce405c9dbdfcbfe28.

spack-environment/packages.yaml

@@ -42,7 +42,7 @@ packages:
     - +fc+ft+X+pdf+gobject
   catch2:
     require:
-    - '@3.0.1'
+    - '@3.4.0'
     - -ipo
   cernlib:
     require: